Furnace charging means



S-Pt 9, 1941 J. F. cRAwFoRD 2,255,379

FURNACE CHARGING MEANS Filed Oct. 22, 1958 2 Sheets-Sheet 1 BYWLMATTORNEY Sept 9, 1941 .1. F. CRAWFORD 2,255,379

FURNACE GHARGING MEANS Filed oct.' 22, 1958 2 sheets-sheei 2 v? G D ocQQOQ Hoppe/2 i INVENTOR. Jo/zrz f Cra w/fora/ A TTORNEY Patented Sept.9, 1941 FUnNAcEcHAnoINo MEANS John F. Crawford, Racine, Wis., assignerto J. I.. Case Company, Racine, Wis., a corporation Application october2z, 193s, serial No. 236,451

21 claims.-

The present invention relates to cupolas, and an object of the inventionis to generally improve the construction and operation thereof.l

Fig. 2 is a similar View, enlarged, of certain portions of the deviceindicated in Fig. 1.

In the operation of cupolas it has long been desirable to be able toutilize metal chips, turn ings, fragments and the like as part of. thecharge to lbe melted, both for the purpose of utilizing the metalinvolved and also for modifying the properties of the metal dischargedfrom the cupola.

coke and metal are introduced through a charging door high up in thefurnace, the introduction of chips with the other metal is generallyunsuccessful because the relatively small particles, when they reach themelting zone, are exposed to an oxidizing atmosphere and consequentlythey are to ay large extent, if not entirely consumed. Furthermore suchof the chips as are not consumed, being relatively much smaller than theother or ordinarycontents of the cupola have a tendency to adheretogether and arch or bridge across the furnace body and arrest thenormal downward movement of the charge. vIn the present instance thesediiiiculties are avoided by introducing the chips at a point remote fromthe charging door where conditions are normally favorable for the rapidmelting of the chips and unfavorable for combustion thereof.

The novel method of operating the cupola ac.- cordingly comprisesintroducing the chips at a point well down in the body of incandescentcoke, for example at about the point where the usual pig iron and scrapmaterial is thoroughly heated and about to liquefy or possibly alreadypartially liquefied. the action may be at this point it appears that thepartially liquefied metal may tend to take In the ordinary operation ofthe, vcupola however wherein alternate charges of While it is not knownexactly what (c1. 26e-fev) protect them from the oxygen in thecombustion zone, heating them and melting them substantially instantly.On the other hand it is possible that thepreponderance of carbon at a.high temperature in this zone may have such an afnity for oxygen as toprotect the chips therefrom, the effects being what might be expected ifthe chips were introduced into a reducing zon in the furnace.

'In any event it appears that chips introduced at such a zone'aresubstantially all melted-and appear promptly inthe accumulation ofmelted metal in the base of the furnace. This results in furtherpossibilities in ythe operation of the cupola, particularly inthe promptand accurate control of the quality ofthe output. For example'thecomposition of the metal in the chips is generally known and can be veryaccurately controlled, whereas the vcomposition ofthe melty ed metal.accumulating `in the bottom of thecupola is apt' to vary. inaccordance. gwiththe, v 1V.

amount of carbon picked up -fromthepokelin its A' descent throughfthefurnace. I f the composi'.. l

.tion of the metal discharging vfrom the furnace is important and a testshows 'an excess of carbon, for example, according to prior vpracticemore steel scrap low in carbon would'be .introduced through the chargingdoor in the usual manner. A considerable time would then elapse beforethis change in proportion would make itself felt inthe composition ofthe output. Then if it turned out that too muchflow carbon metal hadbeen introduced, a similar delay would ensue before further correctioncould be accomplished.

In the practice of the present invention such a correction can beeffected in 'a matter of a few minutes by simply increasing the rate ofintroduction of the chips, assuming a similar situation and that thechips are of low carbon material. This appears to be so because thechips melt immediately and promptly find their way to the accumulatio-nof metal n the base. Of course if a test shows that the change in thechip feeding rate has been too small or too great, correction of thiserror can be made just as promptly. As a result it is a simple matter tohold the quality of the output metal very close to that desired, whereasin `the past much greater fluctuations in the proportions of iron,steel, carbon, etc. have been necessarily tolerated.

As seen in Fig. 1 a typical arrangement for practicing the abovedisclosed method includes a furnace tube, body or casing I of the usualor suitable type having an insulating or other lining the chips andfragments into suspension and 2 and a refractory or heat resistinglining 3, the

casing having a floor 4 covered with a layer of sand or the like 5, ablast chamber 6 surrounding the casing at the lower end, the blast beingsupplied from a suitable source not shown through a duct 1 and passinginto the furnace through openings or tuyres 8 and 9 An opening I isprovided for drawing off the `melted metal into a trough II and anopening or charging door I2 is provided relatively high up in Ithecasing through which the fuel and metal are introduced.

In operation pig iron P, coke C and scrap S are introduced through thecharging door I2 so as to produce alternate layers of metal and coke asshownl the material settling gradually asl the coke is consumed and themetal melted. the

metal reaching a temperature approximatelyat zone Z such that itbecomesplastic and begins to melt and trickle down through the body ofincandescent coke 'and accumulate at I on the sand oor 5, the fused ashfrom the coke, and other impurities, floating on the iron as a layer ofslag I3. y

The desirable point for introduction of the chips appears=to be in theneighborhood of zone Z and accordingly injecting mechanism generallydesignated as I4 is arranged substantially at this point for introducingthe chips.

As seen in Fig. 2 an opening I5 is provided Athrough -the casing I andlinings 2 and 3 in which is fixed, in the present instance, a fittingI6, in the form of a sleeve which may have a flange I1 for a purpose toappear, the injecting mechanism operating through the sleeve.

Said injecting mechanism maybe of any suitable or.well known typecapable of forcing granular or powdered material through sleeve I6, andit is toI be understood that the invention is not to be taken as limitedby the particular disclosed mechanism "I4, or in fact in any mannerexcept as defined by the claims. Mechanism I4 coni--A prises a hopper orreservoir I8 having a trough or auger chamber I9 inthe lower partthereof, and a delivery sleeve arranged to be introduced into abovementioned sleeve I6, sleeve 20 for convenience having a flange 2Iengaged with a flange 22 on the hopper whereby sleeve 20 may be readilyremoved and replaced. A flange 23 also on sleeve 20 approaches flange I1on sleeve I6 when sleeves I8 and 28 are fitted together and a sealingring, clamp or the like 24 is iittedabout the flanges to make' afluid-tight connection. This is desirable because the pressure in thefurnace due to the blast is considerably above atmospheric at this pointand would otherwise cause leakage of objectionable amounts of gas andsmoke into the building.

An auger 25 of suitable or well known form occupies auger chamber IS andmay advantageously extend through sleeve 20 into sleeve I6,substantially or entirely through the wall of the furnace. Rotation ofthe auger will accordingly rfeed chips from hopper I8 through thesleeves and into the furnace, the end of the auger being protected bythe flow of relatively cool chips thereover from the heat of the chargein the cupola.

Difficulty may be experienced with gas and smoke backing up through thebody of chips and sleeve 28 into the hopper I8, objectionable amountsissuing from the hopper. This is avoided by introducing, as for exampleby a hose 21, air or other unobjectionable fluid at a pressure higherthan that obtaining in the furnace, through sealing ring 24, a spud 28or the like extending through the wall of the ring, the fluid iindingitsway through a clearance space 29 to a point spaced materially back fromthe mouth of sleeve amounts of air, for example, at this point producesa flow of clean air in both directions from the mouth of sleeve 28, partof the air passing into the furnace and part of it passing backwardlyinto the hopper, the result being to completely prevent any flow ofsmoke backwardly along the auger.

Auger 25 may be driven in any suitable or well known manner, in thepresent instance, a. motor 30 being carried on bracket 3I and driving,through pulleys 32 and 33 and a belt 34, a speed lreducer generallydesignated as 35. Such reducersbeing well known and the particular typeused being immaterial insofar as the operation of the rest ofthe deviceis concerned, it is not necessary to describe it further than to saythat it has a= shaft 36 driven by pulley 33 and which through internalmechanism drives an output shaft 31 at a reduced speed. Shaft 31 may bedirectly connected with auger `25 and operates at a large reduction inspeed from shaft 38. The speed of shaft 31 may be variable if desired asby a lever 38 although this is not essential since other means iscontemplated for controlling the amount of material fed. The lever maybe locked in various positions by engagement of a detent 39 with one oranother of sockets as 48. Other means is contemplated for lockingthe-lever, or for varying the speed of the auger within the scope of theinvention.

Since the cupola requires some time to reach operating temperature it isusually fired up with the injecting mechanism I4 retracted and sleeve I6plugged with clay or the like. For convenience in so retracting themechanism, hopper I8 is carried by means of a sliding member or trolley4I engaged on a beam, track or the like 42 suitably supported as fromcasing I and for example part of the enclosing building in anywell-known mannr, member 4I being movable on beam 42 wherebyy hopper I8and its attached parts may be readily moved away from casing I. Suitablemeans may be used for so moving hopper I8, in the present instance a bar43 ex,

tending from the hopper in a direction away from the cupola. A rack 44fixed withl the bar en-i gages a gear 45 on the shaft 46 suitablyjournaled in relation to the rack to provide proper interengagementbetween it and the gear, a hand wheel orother suitable means 41 beingfixed with the shaft for rotating it and gear 45. By the use of handwheel 41 mechanism I4 is readily moved toward or away from the cupola asdesired.

'I'he operation of the mechanism is thought to be clear from the abovedescription, the cupola operating in the usual manner except that thechips or other fine material are introduced well below the surface ofthe charge in the zone Z where melting of the larger pieces of metal hasalready commenced, or where the chips will melt substantially as fast asthey are introduced. This obviates any resistance on the part of thecharge already in the furnace to the introduction of the chips andavoids the building up of pressure at the mouth of sleeve I6. The rateof introduction of the chips may be changed by controlling the speed ofauger 25, as by lever 38, although other means are contemplated asequivalent. The injecting mechanism may be readily applied to or removedfrom the injecting opening by means of the gearing 44-45, and smoke andI6. 'The introduction of sufficient" sure introduced throughclearance-'space v29.

The eboveibeing e full and 'complete descrip-- `tion of the novel methodof. operation of a cupola.

and typical mechanism for the practice 'of Vsucll method, what isclaimed as new and-desired to besecured by Letters Patent of-theUnitedStates -is 1. In;l a cupola a body .portion having .side

walls, a bottom for collecting melted metal, a

through the passageway into the contents of the body portion andincluding a delivery sleeve, and

means for introducing a fluid under pressure into the body of granulatedmaterial in said de- 1 livery sleeve peripherally thereof at a pointremoved from that at which said passageway opens into the interior ofthe body portion of the blast'openlng above the bottom, a charging doorl above the blastA opening, and means including an "augerconveyorprojecting into and beyond the `wa1l of the body portion betweenthe blast opening and the charging door arranged for injecting granularvmaterial into lthe body portion at a point where the charge is partlymelted, whereby to melt the granular material before it can be destroyedby oxidation, means for supplying granular material to the auger, andpower driven mechanism for driving theauger.

2. In la cupola a' body -portion having side wells, e `bottom forcollecting melted metal, e

blast opening above the bottom, a charging door above the blast`opening,said side walls providing an opening above the blast opening and belowthe charging door, and injecting mechanism including a hopper, an 'augerconveyor in the hopper including an enclosing sleeve projecting from thehopper, supporting means for the mechanism, and said mechanism beingmovably mounted on the supporting means said enclosing sleevebeingadapted to be inserted in said opening between the blast opening and thecharging door, andfmeans for moving said mechanism on said y supportingmeans for applying or removing said inclosing sleevefrom said opening. Y

3. Inv a chip feeding means for a cupola means .providing an openingvthrough the wall of the cupola and injecting mechanism adapted to beapplied ltov the opening for propelling chips through the opening intothe cupola, and supporting means for the mechanism including a track anda trolley movable on thetrack and connected to support the mechanism.

,4. In a -cupola having a body portion including side walls, a bottomfor collecting melted metal, a blast opening above the bottom, acharging door above the blast opening, said side walls providing an`opening above the blast opening and below the charging door, aninjecting mechanism including a hopper, an auger conveyor in the hopperincluding an 'auger and an enclosing sleeve projecting from the hopperand said auger projecting into land beyond the opening provided in thewall of the cupola.

5. In a cupola a body portion having side walls,.a bottom for collectingmeltedv metal, a blast opening above thebottom, a charging door abovethe blast opening, said side walls providing an opening above the blastopening and below the charging door,`an injecting mechanism including anauger conveyor having an enclosing sleeve' projecting into said openingand partly through said side walls, said auger extending into theopening substantially beyond the end of the sleeve.

6. In a cupola a body portion including side walls, a charging door highup-in the body portion, and a blast opening near the bottom of said bodyportion, said body portion providing a passageway leading through theside walls between the charging door and blast opening, injecting meansfor introducingl granulated material cupola whereby to prevent seepageof gas from the cupola backwardly through the granulated material intothe injecting means.

'1. In a chip injecting means for a cupola a sleeve fixed in the sidewall of the cupola and defining an opening through the wall, injectingmechanism adapted to introduce granular material into the opening forpassage into the body of material in the cupola, and means forintroducing fluid under pressure peripherally into the body of granularmaterial between the inner and outer ends of the sleeve for preventingseepage of gas from the cupola backwardly through the body of granularmaterial. V

8. In a chip injecting means for a cupola a sleeve xed in the side wallof the cupola and defining an opening therethrough, injecting mechanismfor introducing granular material throughthe opening and including asleeve extending into and partly through the first men- A tioned sleeve,there being clearance between said sleeves, and means -for introducingfluid under pressure into the clearance space to prevent seepage of gasfrom the cupola backwardly through the body of granular material beingintroduced sealing band engaging the margins of said flanges f toprevent the escape of iluid therebetween, and a. pipe arranged tointroduce fluid between the ilanges for preventing seepage ofobjectionable gases from the cupola backwardly into .the body ofVgranular material being introduced by the feeding means. y 10. In achip injecting means for a cupol a sleeve fixed in the side wall of thecupola and y opening into the interior thereof, an auger con-.

veyor included in the injecting mechanism and ,having an enclosingsleeve, said enclosing sleeve being inserted in the first mentionedsleeve with clearance and projecting partially therethrough to providean annular passageway leading into the body of chips issuing from saidauger conveyor, and means for introducing air under pressure into theclearance space between the sleeves for penetrating the body of chipsbeyond the enclosing sleeve for preventing ltration of objectionablegases from the cupola through the body of chips in the conveyor. Y

1l. In a chip injecting means for a cupola a sleevefxed in theside wallof the cupola and having an outer iiange, an auger conveyor havlng anenclosing sleeve, said inclosing sleeve belng adapted to be inserted inthe first mentioned sleeve with clearance to provide a passagewayextending longitudinally of the first mentioned sleeve and into thecupola.' a flange on said enclosing sleeve adapted to approach the firstmentioned flange but to be spaced therefrom when said sleeves are placedtogether, a sealing band engaging the margins of said anges to preventthe escape of ud therebetween, and means for introducing a fluid underpressure into the space between said flanges. v

12. In acupola a body portion having side walls, a charging door high upin the side walls, a blast opening near the bottom of the body portion,said `side walls providing an opening between the charging door and theblast opening, and means for injecting granular material through theopening including a conveyor projecting into the cupola beyond the sidewalls, means fordriving the conveyor including power actuated mechanism,and means for selectively changing the rate at which the conveyorintroduces material through the opening.

13. In a chip feeding means for a. cupola, means providing an openingthrough the wall of the cupola and injecting mechanism adapted to beapplied to the opening for propelling chips therethrough, and into thecupola, and means for supporting the mechanism for movement toward andaway from the opening whereby said injecting mechanism may be applied tothe opening when desired,v and-readily removed from the cupola when notin use.

14. In a cupola a "body portion having side walls, a bottom forcollecting melted metal, a blast opening above the bottom, a chargingdoor above the blast opening, said side walls providing an opening abovethe blast opening and below the charging door, and injecting mechanismincluding an auger conveyor, an enclosing sleeve for the conveyor andsupporting means for the mechanism, and said mechanism being Amovablymounted on the supporting means, said enclosing sleeve being adapted tobe'inserted in said opening between the blast opening and the chargingdoor, and -means for moving said mechanism on said supporting means forapplying y or removing said enclosing sleeve from said open- 15. In acupola a body portion having side walls, a bottom for collecting meltedmetal, a blast opening above the bottom, a charging door above the blastopening, said side walls providingV an opening above the blast openingand below the charging door, injecting mechanism including a hopper, aconveyor in the hopper including an enclosing sleeve projecting from thehopper, supporting means for the mechanism an-d said mechanism beingmovably mounted on the supporting means, said enclosing sleeve beingadapted to be inserted in said opening between the blast opening and thecharging door, and means for moving said mechanism on said supportingmeans for applying or removing said enclosing sleeve from said opening.

16. In a cupola, a body portion having side walls, a bottom forcollecting melted metal, a

blast opening above the bottom, a charging doorv above the blastopening, said side Walls providing an opening above thev blast openingand below the charging door, and injecting mechanism including a hopper,an auger conveyor in the hopper, supporting means for the mechanism andsaid mechanism being movably mounted on the supporting means, saidconveyor being adapted to be inserted in said opening between the blastopening and the charging door, and means for moving said mechanism onsaid supporting means for applying or removing said conveyor from saidopening.

.opening above the bottom, a charging door aboveA the blast opening,said side walls providing an opening above the blast opening and belowthe charging door, and injecting mechanism including a hopper, an augerconveyor in the hopper including an auger having an enclosing sleeve andprojecting from the hopper, supporting means for the mechanism and saidmechanism being movably mounted on the supporting means, said conveyorbeing adapted to be inserted in said opening between the blast openingand the charging door, and means for moving said mecharism on saidsupporting means for applying or removing said conveyor from saidopening.

18. In a cupola, a body portion having sidev walls, a bottom forcollecting melted metal, a blast opening above the bottom, a chargingdoor above the blast opening, said side walls providing an opening abovethe blast opening and below the charging door, and injecting mechanismincluding a hopper, an auger conveyor in the 17. In cupola, a bodyportion having side walls,

a bottom for collecting melted metal, a blast hopper including anenclosing sleeve projecting from the hopper, supporting means for themechanism, and said mechanism being movably mounted on the supportingmeans, said conveyor being adapted to be inserted in said openingbetween the blast opening and the charging door,

and means for moving said mechanism on said supporting means forapplying or removing said conveyor from said opening.

19. In a cupola, a body portion having side walls, a bottom forcollecting melted metal, a blast opening above'the bottom, a chargingdoor above the blast opening, said side Walls providing-an opening abovethe blast opening and below the charging door, and injecting mechanismincluding a hopper, an auger conveyor in the hopper including anenclosing sleeve projecting from the hopper, supporting means for themechanism and said mechanism being movably mounted on the supportingmeans, and said enclosing sleeve being adapted to be inserted in saidopening between the blast opening and the charging door.

20. In a cupola, a body portion having side walls, a bottom forcollecting melted metal, a. blast opening above the bottom, a chargingdoor above the blast opening, said side walls providing an opening abovethe blast opening and below the charging door, and located substantiallyat a level where the usual melted, an injecting mechanism including aconveyor having an enclosing sleeve projecting into said opening andpartly through said side walls, and said conveyor extending into theopening substantially beyond the end of the sleeve for acting onmaterial being injected at a region beyond the end of the enclosingsleeve.

21. In a cupola a body portion having side JOHN F. CRAWFORD.

metal charge is partly,

